The Sierra Club on Thursday filed suit in federal court claiming that two major coal-fired power plants operated by Wisconsin Power & Light Co. were upgraded over the years without installing modern pollution controls required by the Clean Air Act.

The suit charges the Madison utility made modifications to its Nelson Dewey power plant in Cassville in southwestern Wisconsin and its Columbia power plant near Portage without adding pollution controls. WP&L is a subsidiary of Alliant Energy Corp., Madison.

The suit is the latest in a series of Sierra Club suits targeting pollution from coal-fired power plants across Wisconsin.

Another suit by the environmental group and Clean Wisconsin has targeted air pollution from the We Energies Valley power plant in Milwaukee’s Menomonee Valley. Sierra Club has also filed suit over pollution by coal plants operated by Dairyland Power Cooperative of La Crosse and Wisconsin Public Service Corp. of Green Bay.

“The pattern here is that our aging fleet of coal plants can’t even meet current standards, so it sets us up for making a choice about whether we should be throwing good money after bad” to retrofit coal plants to meet emerging, stricter standards, said Jennifer Feyerherm of the Sierra Club’s Beyond Coal campaign.

WP&L has proposed adding pollution controls at the Columbia power plant, in an investment projected to cost $627 million. The state Public Service Commission has yet to rule on that proposal, and the Sierra Club is challenging that the controls proposed don't go far enough to reduce air emissions from Columbia.

“We’re disappointed that the Sierra Club has opted for this approach,” utility spokesman Scott Reigstad said of Sierra Club's suit. “We disagree with the claims the Sierra Club is making in its complaint. We intend to vigorously defend against the action.”

The court actions come as the state Public Service Commission is studying whether to shut down aging coal-fired power plants in Wisconsin because of the state's power glut, and as the U.S. Environmental Protection Agency is commencing regulation of coal plants to curb emissions of carbon dioxide as well as a series of other pollutants.

Earlier Thursday, another environmental group, the Clean Air Task Force, issued a report that examines the health costs of coal-plant pollution. More on that is available here.

About Thomas Content

Thomas Content covers energy, clean technology and sustainable business. A series he co-wrote on energy and climate change won top honors in 2008 from the National Press Foundation.

Energy Business News

EnSync Energy Systems has shipped a utility-scale energy storage system to South Korea, the Menomonee Falls company said.

The 500-kilowatt-hour system incorporates enough battery power for four or more hours of discharge, using EnSync’s zinc bromide flow batteries as well as power electronics and converters.

Formerly known as ZBB Energy, EnSync is focused on smaller energy storage systems for commercial buildings such as projects it's built in Hawaii in recent years. But it's also been working on larger energy storage systems.